Update: This article has been edited to remove references to caramel coloring. What do trans fat, caffeine and genetically modified organisms (GMOs) have in common? Each of these distinct, seemingly unrelated food controversies actually shares a common origin: the generally recognized as safe (GRAS) process. In fact, a wide range of food controversies — from sweeteners to energy drinks — are directly related to GRAS. GRAS is a legal term describing certain food ingredients that are safe enough to enter the market without prior government approval or restrictions. GRAS allows foods to enter the food system through a streamlined process. Under the streamlined process, companies, rather than the government, determine whether an ingredient is GRAS. The self-determined GRAS status of an ingredient is significant because companies can immediately put GRAS ingredients on the market; no government agency has to sign off on their safety. The majority of ingredients in the U.S. food system today are added as GRAS. As a result, the GRAS process also underlies most food-related controversies. The following list demonstrates a wide range of issues that trace back to GRAS.  A List of GRAS Controversies Trans Fat: The trans fat controversy concerns human health and heart disease. Trans fat increases the risk of heart disease, which is the leading cause of death in the U.S. Partially hydrogenated oils (PHOs), a major source of trans fat in processed foods, are GRAS. So, despite the known health risks of trans fat, companies have used PHOs in processed foods for years with little to no government involvement. Only recently has the U.S. Food and Drug Administration (FDA) proposed to step in and de-GRAS PHOs. If FDA does de-GRAS PHOs, companies will have to work more closely with FDA and obtain its approval before adding PHOs to food in the future. GMOs: GMOs are arguably the most controversial substances added to food today. The term “substance” may not adequately describe GMOs. More accurately, GMOs are the result of scientific methods used to introduce new traits or characteristics to organisms. Although studies have not linked GMOs to human heath, some consumers nonetheless believe that GMOs have negative human and environmental health consequences. Most GMO debates focus on labeling; however, GMO ingredients may be legally added to food via the GRAS process. In a 1992 Policy Statement, FDA clarified that it will treat GMO substances as “the same or substantially similar” to substances commonly found in food. Thus, if a non-GMO version of an ingredient can be added as GRAS, then, in some cases, so can its GMO counterpart. For example, soybean oil is GRAS. Thus, companies can use soybean oil derived from GMO soybeans without having to do any additional safety testing or obtain any special governmental approval. Notably, FDA does have a voluntary consultation process for GMO ingredients. So before a GMO ingredient is added via the GRAS process, the FDA has likely reviewed its safety. In the case of soybean oil, FDA has reviewed and approved the safety of GMO soybeans. Nanotechnology: Nanotechnology refers to a technology where scientists manipulate nanomaterials, e.g. materials too small to be detected by regular microscopes. Nanotechnology is an emerging technology that has many potential uses in food such as extended shelf life and flavor enhancement. So far, nanotechnology has not received the same attention as GMOs. Yet the controversies are similar. Like GMOs, studies have not definitively linked nanotechnology to human health. But some consumer groups, such as Friends of the Earth, have raised concerns about potential human and ecological consequences. Also similar to GMOs, companies may be able to add nanotechnology versions of GRAS substances without any additional review or special approval. FDA issued draft guidance for the food industry, which suggested that most nanotechnology ingredients likely do not qualify as GRAS. But the guidance is a suggestion, not a requirement. So, ultimately, companies still decide whether to treat nanotechnology substances as GRAS. If a company does determine that a substance is GRAS, then it can add it to food without informing FDA or doing any additional safety testing. Sweeteners: Today’s sweeteners come in all different forms, and each form seems to have its own controversial characteristics. For instance, High Fructose Corn Syrup (HFCS) is a liquid sweetener that has replaced traditional sugar in most processed foods in the U.S. Studies have potentially linked HFCS to diabetes. To avoid the negative press on HFCS, in 2012 the Corn Refiners Association asked FDA to change the official name of HFCS’s GRAS determination to “corn sugar.” FDA declined. Artificial sweeteners are substances that have been formulated to replace sugar; they generally contribute the same sweetness as sugar at smaller amounts. Although artificial sweeteners may have been added as GRAS substances in the past, the FDA currently regulates these substances as food additives, not GRAS. This means that FDA must approve the use of these substances before a company can put them on the market. But at least one sweetener, Stevia, is added to food as GRAS. Even the most basic sweetener, sugar, is a controversial substance directly related to GRAS. Consumer groups, especially those concerned about obesity and children’s health, have criticized the high amounts of sugar used in food today. Sugar was one of the first GRAS substances, but, over the years, companies have greatly increased the amount of sugar added to processed foods. So, while most consumers do not question the GRAS status of sugar altogether, some question whether very high levels of sugar qualify as GRAS. Salt: Salt raises blood pressure, which has a strong relationship to the risk of cardiovascular disease. Like sugar, some groups have questioned the GRAS status of salt as companies continue to add increasingly large amounts of salt to processed foods.  Monosodium glutamate (MSG): MSG is a notoriously controversial food substance, but the controversy seems to have died down over the years. MSG is the sodium salt of glutamic acid, which is an amino acid. MSG occurs naturally in many foods, but it can also occur through human manipulation. Some consumers claim to have allergic reactions to MSG, and some groups claim that MSG may contribute to neurological and physiological disorders. MSG first entered the food system as GRAS. After people raised issue with it, FDA reviewed its safety, but MSG remains GRAS. Caffeine: Like sugar and salt, the controversy surrounding caffeine is more related to the levels of use than the risks of the substance itself. Caffeine is one of the original GRAS substances, but companies are using such high levels of caffeine in their energy drinks that FDA has stepped in and is now questioning the safety of caffeine at those levels.  Another abuse of caffeine as GRAS occurred when companies mixed it with alcohol. Eventually, FDA stepped in and declared that caffeine mixed with alcohol is not GRAS and therefore requires premarket approval. This declaration led to the notorious change in the well-known Four Loko beverage. Conclusion This list of food-related controversies is not exhaustive, nor does it begin to cover every GRAS substance. But it demonstrates the reach and impact of the GRAS process on the U.S. food system, as well as links a wide range of issues to a common legal source.